1. Field of the Invention
The present invention relates generally to clean room constructions for electronics or biomedical, manufacturing or research institutions. More specifically, the present invention relates to a trim arrangement which allows trim members to be selected and quickly and easily fitted onto panels without the need for bonding or the need to be fastened with screws, and which can be removed and re-used when the clean room layout is changed to accommodate new requirements.
2. Description of the Related Art
Presently, when constructing clean room walls in which there is a corner at a junction of two walls, a corner angle molding is glued to the wall material to seal and dress the corner of the two intersecting wall panels. This construction, however, usually prevents the reuse of the panels and molding associated with such corner construction. An alternative arrangement is such that the corner angle moldings are fastened with screws. However, this technique suffers from the drawback that the insertion and removal of the screws creates microfine particles during installation or renovating of the panels and thus gives rise to a high possibility of contamination.
FIGS. 1 and 2 show an example of a conventional corner angle construction. In this example, an outside corner trim 50 is used to interconnect two 0.5" aluminum panels 52. As will be appreciated, the panels 52 are connected to two vertically extending double sided aluminum studs 54, by way of wall panel clips 56. In order to prevent contamination through gaps which inevitably occur in such circumstances, foam gaskets 58 are disposed in the illustrated positions. An inside corner trim 60 is shown fastened to the panels by way of screws 62.
FIGS. 3 to 12 show various different types of wall panels and modules which can be used with the connection with a so-called "studless wall system". FIG. 3 shows a solid panel 70; FIG. 4 shows a single door module 72; FIG. 5 shows a double door module 74; FIG. 6 shows a window panel 76; FIG. 7 shows an auto door module 78; FIG. 8 shows an air return panel 80; FIG. 9 shows a pre-wired panel 82; FIG. 10 shows a solid door 84; FIG. 11 shows a half glazed door 86; and FIG. 12 shows a full glazed door 88. As will be appreciated, these panels can be relatively complex in nature and therefore relatively expensive. In the event that the panels have other members bonded permanently to them, each time a change in floor plan or layout occurs, considerable waste is apt to occur. This, of course, leads to an increase in cost in that many panels usually cannot be recycled unless the exact same corner construction is required.
FIGS. 13 to 17 show various types of structural fasteners and transition elements which are used in the above-mentioned "studless wall system", to provide connections between the wall panels and ceilings and floors of the building in which the clean room is being constructed. FIG. 13 shows a head track 90 which is fastened to an existing ceiling or the like and used to establish a connection with the upper edges of the panels which are used to form the walls. FIG. 14 shows a floor track 92 which is used along the lower edges of the panels. FIG. 15 shows a I/O corner tube 94 while FIGS. 16 and 17 respectively show a three piece batten set 96 and a glazing batten set 98 which use screws to establish a connection between the inner and outer members.
Clean rooms tend to require a considerable amount of so-called "bulkhead" equipment which extend through the walls of the clean room. As this equipment is usually very expensive and delicate, it is inevitably stored in a safe place while the construction or renovation of the clean room(s) is actually taking place. This means that, in order to complete the wall structure, it is necessary to install temporary panels and when the layout is basically completed, bring the production equipment in. However, this means that a number of the wall panels and associated constructions must be in part removed or torn down in order to allow the equipment to be moved into the required positions and the panels which accommodate the bulkheading arrangements to be installed in place of the temporary ones. This, of course, complicates construction and leads to wasteful and time consuming construction and reconstruction types of operations. It also opens up the clean room environment to contamination. Even when screws are used in place of bond, the structures still require that the screws be removed to allow a panel or panels to be removed or replaced so as to allow ingress and installation of the production equipment. The screws must then be reinserted.
As mentioned above, the use of screws tends to create micro-fine particles which are highly apt to create problems in the clean room environment. In order to eliminate this contamination problem, it has been proposed to use snap-in types of connectors and to provide trim members which can be pressed and secured in place without the need for screws to keep them in place. FIGS. 18 and 19 show a trim 100 which has been proposed for use with a stud based wall system. As will be clearly appreciated from FIG. 18, this trim 100 includes a barbed member 101 which is adapted, as shown in FIG. 19, to fit in between the fingers 102 of a springy T-shaped clip member 104, a support arm 106 and a seal seat 108. As shown in FIG. 19, the T-shaped clips 104 are arranged to be slipped into a T-channel groove 110 which extends along the length of one face of a stud 112. These clips are typically about 6" long and are spaced at intervals along the length of the stud 112 which is approximately 8' in length. The support arm 106 is arranged to rest against an edge portion of the stud 112, while the seal seat 108 is arranged to engage an elastomeric rope 114 or the like, in a manner which seals off the gap which tends to be produced between the edge of the trim 100 and the existing wall or structure 116 in which the prefabricated structure is being erected.
However, during the development of this invention, it was discovered that the trim arrangement 100 shown in FIG. 18 suffers from a number of drawbacks. The most disconcerting of these is that the trim tends to rotate about the barb 101a which is retained in the clip 104, and thus open up a clearance between the trim 100 and the outer surface of the wall panel 118. Apart from being unsightly, it tends to open a gap through which contamination can find its way into the interior of the clean room.